Technicians are testing pillar-style roadside sensors like those deployed to ports of entry and some highway weigh stations. The sensors detect neutrons and gamma rays emitted by lethal nuclear devices or radioactive isotopes that could be dispersed by less sophisticated explosives in a “dirty bomb.”

The scientists also are testing sensors in vehicles, including white ambulance-style vans, black SUVs and a Jeep loaded with sophisticated radiation sniffers and computers.

The tests aim to see whether the 30 or so devices available commercially can distinguish a bomb from less harmful sources of radioactivity, such as a person who has had a radioactive isotope injected during a medical procedure, or household items like kitty litter and floor tiles that contain natural trace amounts….

Detecting radioactive materials in public places is an evolving science, Oxford said. There are no national standards for devices that range from the size of a steam iron to the two-door prototype “Smart Jeep.”

The next generation of hand-held detectors should be able to identify radiation sources without the need to open shipping containers using what Oxford calls “discrimination capability.”

This is very important work on the most important research challenge for our nation’s homeland security. There are no guarantees, but hopefully this testing will help produce a breakthrough in the state of detection technology.